Feature-tracking CMR can detect LV strain abnormalities in patients with PH and preserved or mildly depressed LVEF, with greatest abnormality in the septum. The association between septal strain and right ventricular end-diastolic volume index suggests that ventricular interdependence may be a mechanism of LV dysfunction in PH. Feature-tracking CMR may be useful for identification of LV dysfunction before LVEF significantly declines in patients with PH. The feasibility of detecting LV strain abnormalities in patients with PH shown by this study paves the way for a variety of future investigations into the applications of LV strain in this patient population.
Object
This work presents a highly-accelerated, self-gated, free-breathing 3D cardiac cine MRI method for cardiac function assessment.
Materials and Methods
A golden-ratio profile based variable-density, pseudo-random, Cartesian undersampling scheme was implemented for continuous 3D data acquisition. Respiratory self-gating was achieved by deriving motion signal from the acquired MRI data. A multi-coil compressed sensing technique was employed to reconstruct 4D images (3D+time). 3D cardiac cine imaging with self-gating was compared to bellows gating and the clinical standard breath-held 2D cine imaging for evaluation of self-gating accuracy, image quality, and cardiac function in eight volunteers. Reproducibility of 3D imaging was assessed.
Results
Self-gated 3D imaging provided an image quality score of 3.4 ± 0.7 v.s. 4.0±0 with the 2D method (p=0.06). It determined left ventricular end-systolic volume as 42.4±11.5mL, end-diastolic volume as 111.1±24.7 mL, and ejection fraction as 62.0±3.1%, which were comparable to the 2D method, with bias±1.96×std of −0.8±7.5 mL (p=0.90), 2.6±3.3mL (p=0.84) and 1.4±6.4% (p=0.45) respectively.
Conclusion
The proposed 3D cardiac cine imaging method enables reliable respiratory self-gating performance with good reproducibility, and provides comparable image quality and functional measurements to 2D imaging, suggesting that self-gated, free-breathing 3D cardiac cine MRI framework is promising for improved patient comfort and cardiac MRI scan efficiency.
To evaluate the effect of MRI blood pool contrast agent on 4D flow image quality and ventricular volume measurements. Adult patients referred for clinical cardiac MRI (n = 22) were imaged with 4D flow. Patients with renal failure (n = 10) received ferumoxytol, and the remainder (n = 12) received gadofosveset trisodium. Image quality was assessed with (1) signal-to-noise ratio (SNR); (2) contrast-to-noise ratio (CNR); and (3) 5-point Likert scale based on endocardial border definition (1 = none; 2 = partial but unable to visualize; 3 = able to roughly estimate; 4 = visible for most of the cardiac cycle; 5 = excellent definition). A subset (n = 15) had short axis steady-state free precession (SSFP) cine imaging allowing for comparison of standard volumetric measurement technique with 4D flow derived volumetric measurements. 4D flow studies using ferumoxytol demonstrated a higher median Likert score of 5 (IQR, 5-5) versus 3 (IQR, 2-3). Median cavity SNR and CNR were higher for ferumoxytol compared to gadofosveset trisodium [65 (IQR, 50-74) versus 22 (IQR, 14-28), p < 0.001; and 40 (IQR, 32-49) versus 4 (IQR, 3-10), p < 0.001]. Good correlation (p < 0.001) was seen between SSFP and 4D flow measured ventricular volumes (ESV and EDV) with ferumoxytol (r = 0.998, mean difference = 1.2 mL, LOA = - 7.7-10.1 mL) and gadofosveset trisodium (r = 0.942, mean difference = - 2.7 mL, LOA = - 35.7-27.1 mL). Ferumoxytol used off-label as an MRI blood pool contrast agent offers an attractive alternative to gadofosveset trisodium in patients with renal failure, with excellent 4D flow image quality and good correlation of volumetric measurements compared to the CMR reference (SSFP).
Uptake of the radiopharmaceutical F-FDG visualized by PET imaging can reflect abnormal myocardial inflammation. When utilized in conjunction with other imaging modalities, such as echocardiography, PET F-FDG imaging can help distinguish between active cardiac sarcoidosis and other etiologies of nonischemic cardiomyopathy. We present a case of a 46-year-old man with nonischemic cardiomyopathy and ventricular tachycardia who underwent an echocardiogram suggestive of cardiac Chagas disease. A subsequent F-FDG PET demonstrated abnormal hypermetabolism. The diagnosis was confirmed by positive serologic examination results.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.